1. Field of the Invention
This invention relates generally to ram blowout preventers. In particular, the invention relates to apparatus for securing the bonnet to the housing of a ram blowout preventer. Still more particularly, the invention relates to an apparatus for securing and retracting a bonnet from a blowout preventer housing.
2. Description of the Prior Art
Various apparatus is known in the prior art for securing and retracting a bonnet to a ram blowout preventer housing. One prior art apparatus has included a bonnet which is hinged at one side of the blowout preventer body and is secured to the blowout preventer body by means of bonnet bolts. When it is desired to open the bonnet with respect to the blowout preventer housing for the purpose of servicing a packer or ram assembly, the bonnet bolts are disconnected from the bonnet in the housing and the bonnet is moved outwardly on the hinge thereby exposing the ram assembly.
Another prior art apparatus is known by which rods are secured within the body in the blowout preventer housing and the bonnet slidingly engages the rods. The bonnet housing is constructed to completely envelope the rods. Separate bonnet bolts are provided to secure the bonnet to the blowout preventer housing. When it is desired to open the bonnet, the bonnet bolts are first removed and then the hydraulic system for closing the ram is engaged thereby forcing the bonnet away from the housing by the action of the hydraulic system. The bonnet slides outwardly from the housing on the rods secured within the housing.
There has developed a need to provide a bonnet securing and retracting apparatus for a ram blowout preventer which is simple and lightweight, a system especially adapted for blowout preventers of limited size and weight which may be used, for example, in a mobile workover blowout preventer system.